Various attempts have been made in the past to develop carpentry levels that can be used to align surfaces relative to one another and also determine the angle, that certain surfaces are disposed with respect to the horizontal and/or vertical plane.
Some of the prior art devices that have been developed comprise nothing more than elongated rigid tools having a plurality of bubble elements and other angular indicating means associated therewith.
Other prior art devices employ a spirit level that is laterally or vertically translatable along a flat edged support member.
Still other prior art devices employ split body levels devices, wherein the level sections are pivotally secured to one another.
Yet other prior art devices employ adjustable length single spirit level apparatus, having pivoted legs disposed on the ends of the adjustable sections, so as to elevate the spirit level and give an accurate indication of the angle of slope between the two supported ends.
Examples of some of the aforementioned prior art devices may be seen by reference to the following U.S. Pat. Nos.: 2,691,829; 1,029,744; 832,326; and, 2,692,440.
While all of the above cited references are adequate for their intended purposes, they leave a lot to be desired from the standpoint of being an all around multi-purpose carpenters level. In particular, these devices did not have the requisite versatility or ease of operation that would have gained them the immediate and widespread acceptance in the carpentry trade that they presently lack, both singularly and collectively.